title: Vasoactive intestinal peptide decreases MYCN expression and synergizes with retinoic acid in a human MYCN-amplified neuroblastoma cell line.
abstract: Neuroblastoma is a pediatric tumor which can spontaneously regress or differentiate into a benign tumor. MYCN oncogene amplification occurs in 22% of neuroblastomas and is associated with poor prognosis. Retinoic acid (RA), a molecule able to induce differentiation and to decrease MYCN expression, is used in the therapy of neuroblastomas. The neuropeptide vasoactive intestinal peptide (VIP) is known to control proliferation or differentiation of numerous cancer cells. In vitro, VIP induces differentiation of neuroblastoma cells. To determine whether VIP could modulate MYCN expression, we carried out real-time quantitative RT-PCR and Western immunoblot analyses in human neuroblastoma SH-SY5Y and IMR-32 cells. The results indicated that VIP reduced MYCN mRNA and protein expression, especially in the MYCN-amplified IMR-32 cells, with a maximal and transient decrease by approximately 50% after few hours of treatment with VIP at 10(-6) M. This effect was compared to that of RA at 10(-5) M, which induced a diminution of MYCN mRNA expression by approximately 25% after few days of treatment. This indicated that VIP and RA display complementary kinetics. Cotreatments showed that VIP and RA had synergistic effects on regulation of expression of MYCN proteins. VIP and RA cotreatments regulated also expression of two MYCN target genes, SKP2 and TP53INP1. These results suggest that VIP, in combination with RA may have a potential therapeutic benefit in neuroblastomas with MYCN amplification, a genetic abnormality associated with poor prognosis.
authors.affiliation: KInstitut de Physiologie et Biologie Cellulaires, Université de Poitiers, CNRS, Poitiers, F-86022, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Chevrier
authors.forename: Annie-Claire
authors.initials: AC
authors.lastname: Meunier
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Cochaud
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Muller
authors.forename: Corinne
authors.initials: C
authors.lastname: Chadéneau
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D048430:Cell Shape / Q000187:drug effects; D015536:Down-Regulation; D004357:Drug Synergism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D000071447:N-Myc Proto-Oncogene Protein; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D044786:S-Phase Kinase-Associated Proteins / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D002352:Carrier Proteins; D006360:Heat-Shock Proteins; C459801:MYCN protein, human; D000071447:N-Myc Proto-Oncogene Protein; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D012333:RNA, Messenger; D044786:S-Phase Kinase-Associated Proteins; C429767:TP53INP1 protein, human; D014660:Vasoactive Intestinal Peptide; D014212:Tretinoin